Individuals with colon cancer who took multivitamins after surgery, either before, during or after chemotherapy experienced no significant change in their risk of the cancer coming back, or dying from colon cancer, wrote researchers from the Dana-Farber Cancer Institute in an article published in the Journal of Clinical Oncology. While no benefits were observed for stage III colon cancer patients, there were not any reported detrimental side effects either.

Main author, Kimmie Ng, MD, MPH, a gastrointestinal oncologist at Dana-Farber, explained that about 30% of US patients take multivitamins to treat cancer and other chronic (long-term) diseases; this is in spite of conflicting evidence about their efficacy. Between 26% and 77% of cancer survivors say they took/take multivitamins.

Kimmie Ng:

With such a high proportion of cancer patients utilizing multivitamin supplements in the belief that it will help them fight their cancer, we felt it was important to really examine the data to see what impact multivitamins had on cancer recurrence and survival.

Two questionnaires were given to patients, 1,038 completed them initially, while 518 did so while receiving chemotherapy.

810 patients were still cancer-free when they completed the second survey six months after chemotherapy; 416 of them said they had been taking multivitamins.

Ng and team did not find a statistically significant different between the rates of disease-free survival, recurrence-free survival, and overall survival between individuals who took multivitamins and those who didn’t.

The team also factored in such variables as socio-economic status, household income, multivitamin dosage, individual vitamin dosage, as well as consistency of multivitamin, and found they did not influence their findings.

They did detect a slight beneficial link between age and weight and multivitamin use when undergoing chemotherapy. Patients aged less than 60 years as well as obese individuals experienced some survival benefits. When multivitamins were taken after chemotherapy was complete, no benefits were detected for either subgroup, the authors reported.

The researchers stressed that further studies are required to confirm their findings, as well as determining whether other factors might have had an impact on outcomes.

Senior author, Charles Fuchs, MD, director of gastrointestinal oncology at Dana-Farber, said:

This study adds to a growing body of research that questions the purported benefit of multivitamin use, and it underscores the need to investigate the use of individual vitamins, such as vitamin D, which may, in fact, provide real benefit.

Dr. Fuchs added that the average multivitamin normally has only a small to modest amount of vitamin D.

The colon is the longest part of the large intestine and the lowest part of the digestive system. Inside the colon, water and salt from solid wastes are extracted before the waste moves through the rectum and exits the body through the anus.

Cancer is a class of diseases characterized by out-of-control cell growth, and colon cancer forms when this uncontrolled cell growth initiates with cells in the large intestine. Most colon cancers originate from small, noncancerous (benign) tumors called adenomatous polyps that form on the inner walls of the large intestine. Some of these polyps may grow into malignant colon cancers over time if they are not removed during colonoscopy. Colon cancer cells will invade and damage healthy tissue that is near the tumor causing many complications.

After malignant tumors form, the cancerous cells may travel through the blood and lymph systems, spreading to other parts of the body. These cancer cells can grow in several places, invading and destroying other healthy tissues throughout the body. This process itself is called metastasis, and the result is a more serious condition that is very difficult to treat.

Colon cancer is not necessarily the same as rectal cancer, but they often occur together in what is called colorectal cancer. Rectal cancer originates in the rectum, which is the last several inches of the large intestine, closest to the anus.

In the United States, about 112,000 people are diagnosed with colon cancer each year.

Click here to view a more detailed article on colon cancer.

“Circulating 25-Hydroxyvitamin D Levels and Survival in Patients With Colorectal Cancer”
Kimmie Ng, Jeffrey A. Meyerhardt, Kana Wu, Diane Feskanich, Bruce W. Hollis, Edward L. Giovannucci, Charles S. Fuchs
Journal of Clinical Oncology, Vol 26, No 18 (June 20), 2008: pp. 2984-2991
© 2008 American Society of Clinical Oncology.
DOI: 10.1200/JCO.2007.15.1027

Written by Christian Nordqvist